Compound geared turbine.



' 1. c. SHAW. CQMPOUND GEARED TURBiNE.

AFFLIQATION FILED MAR. 29. i916- Patentd Aug. 7;!1917.

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JAMES C. SHAW, PHILADEIPHIA, EENNSYLVANIA, ASSIGNOR TO THE WILLIAM CRAIVIP & SONS SHIP & ENGINE BUILDING COMPANY, A CORPORATION OF PENN- .SYLVANIIL COMPOUND GEARED TURBINE.

Patented Aug. *7. 1917.

ppiieation med March 29, 191e. serial No. 87,429.

To au '1r/wm 19mm/concern:

Be it known that I, JAMES C. Sriaw, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State oflennsylvania, have invented certain new and useful Improvements in A Compound Geared Turbine Propulsion, of

rate high and low which the following is a full, clear, and exact specification.

This invention relates to marine propulsion, and has for its object to provide a system of compounded geared turbines of sepapressure units in order to improve the economy at both full' and re duced powers.l The invention is especially applicable to naval vessels, which require to have provisioi'i for maximum speed with economy of fuel consumption, and are also required to operate most of the time under economical reduced speeds.

In carrying out the object of the invention, a propeller shaft is provided with a gear, which gear is driven by separate pinions on two or more turbine shafts, each type in shaft preferably having a high pressure and a low pressure unit, the high pressure unit on. one shaft being connected 1n series with the low 'pressure unit on the othershaft. At full power, both shafts having a high and a low pressure unit in tandem operate at the same speed to drive the common gear on the propeller shaft, while at reduced powers one high pressure unit and its connected low pressure unit are cut out and run in the condenser vacuum. By proportioning one of the high and low greater proportion sure than the other,

pressure units to take a of the totalfiuid presat least two economical `low powers can be obtained, according to which high and low pressure combination is used. In order to enable thesevtwo high pressure and low pressur/eiiinit combinations to rotate at the saine speed/under full power while developing respectively different powers when operating alone, one of the low pressure units is made larger than the other, and as herein shown is of the divided iiow which the sections are equal to each other and also to the other low pressure unit. In such an arrangement, one of the high pressure units while the remaining hgh pressure unit and sure unit will take the remaining one-third,

and the divided low pressure unit will preferably. take two-thirds ofthe v -Of course, other proportions of power consuniption can be adopted, but the lower pressure blading in such cases will not be identical. Reversing mechanism is provided at the end of the single low pressure unit, and both of the low pressure units will be connected to a common condenser.

In such an arrangement, the high pressure units and the reverse unit are preferably of all wheel construction, while the low pressure sections are preferably identical in construction and interchangeable, and are ordinarily of all drum construction, although if desired they may be of wheel constructions. The invention also presents a further advantage in that by the provision of three low pressure units the fluid velocity through the last blades can be such as conn d-ucive to best efficiency, thereby permitting of more rugged and shorter exhaust blade design. l

The invention will be more fully understood in connection with the accompanying drawing, whereinl represents a propeller shaft having a' large gear 2 with which mesh pinions 23, 23, on shafts 24, 25, respectively. The shafts 24, 9.5, are connected by ilexible couplings 9,

10, to shafts 26, Q7, which are themselves coupled at 7 and 8, respectively, tothe high pressure turbine'shafts 28, 29, respectively. On shaftsfZS and'26, respectively, are a high pressure all 'wheel stage unit 3 and alow pressure divided flow, preferably drum stage unit 4 having supply pipes 19, 20, and' stages similar to the wheels in high pres-l sure units 3 and 5. The exhaust from the high pressure unit 3 is led by pipe 31 to the low pressure unit 6 and the exhaust from high pressure unit 5 is led by pipe '12 to pipes 19 and -2O leading to the divided sections of low' pressure unit 4. The main steam supply is by pipe 13 whichA branches by pipes 30, 35, to the respective high prsisure units 3 and 5. Throttle valves 36, 37

-control the supply to the yrespective high pressure units and 38 is the main shut off valve. For reversing, steam is supplied by pipe 2l to reversing unit 17 through valve 39.

'ions of different sizes either in stock at the yard or on board ship. The power on the two pinions, aswell as the revolutions, will be thev sa-me when turbines 3 and 6, and turbines 5 and 4, develop equal powers. This will be the case if turbines 3 and 6 each dcvelcp one-sixth of the total power, andturbine 5 one-third of the power, and each half of turbine l one-sixth of the power. It is permissible, however, to apply more power through one of the pinions than through the other, by changing the proportions.' The pinions are duplicates and when operatingi at reduced power are not stressed lo their maximum, heilig only stressed to their maximum when operating underv full power, which is only for a small fraction of the total time the vessel is in operation. Hence the te `eth are less liable to breakage, and have longer life than would otherwise be the case. At full power, all the turbines are used and at two-thirds down to approximatel-y one-third power turbines 5 and l are used, and the other two revolved in vacuum. At approximately one-third powcand less, turbines 3 and l are used, andthe. other two being revolved in vacuum. By having three low pressure turbine parts, the fluid velocity through the last blades can be kept low enough to produce the best efficiency. This also permits of more rugged exhaust blade. design and enables stresses due to centrifugal forces to be kept low at the roots of the blades owing to the reduced exhaust blade length. An economy is obtained both in initial cost and in maintenance, as well as in time required for repairs, by having the low )ressure sections alike, as herein described.

y operating only two turbines at reduced powers, the economy is greatly improved over that where it is attempted to operate all turbines at all times, because in the present invention the blading at both high pressure and low pressure ends is more effective and eflicient, even though the other turbines be operated idle in vacuum, than Where it is sought to obtain a large (range of power by operating all the turbines more or less throttlcd. l'Vhere `it is not desired to revolve the idle high pressure turbine in vacuum'when operating at reduced power, it is simply necessary to uncouple it'zzt ycoupling 7 or 8, depending upon which of the high pressure units is being used.

The invention is not to be restricted to the rality of shafts 'speeds of revolution, and means for precise construction herein shown as the particular'modification here disclosed may be varied without departing from the scope of the appended claims.

{aving thus described my invention, I declare that what I claim as new and desire t0 secure by Letters Patent., is

l. In a marine turbine installation, a plurality of shafts cach having a high pressure unit and a. low pressure unit, a propeller shaft geared to both of said shafts, and nvans connecting each low pressure unit on one shaft in series with the high pressure unit on the other shaft.

2. In a marine turbine installation, a plurality of shafts each having a high pressure unit and a low pressure unit, a propeller shaft geared to both of said shafts, and means connecting eaeh low pressure unit on one shaft in series with the high pressure unit on the lother shaft, said respective high and low pressure turbines passing predetermined portions of the total Huid pressure at equal speeds of revolutipn. 3. In a marine turbine installation, a plulach having ay high pressure unit and a low pressure unit, a propeller shaft geared to both of said shafts, and means connecting each low pressure unit on one shaft in series with the high pressure unit on the other shaft, said respective high and low pressure turbines passing predetermined unequal portions of the total fiuid pressure at equal speeds of revolution.

l. ln a marine turbine installation, a plurality of shafts each having a high pressure yunit and a low pressure unit, a propeller shaft geared to both of said shafts, means connecting the low pressure unit on each shaft in series with the high pressure unit on thc other shaft, said respective high and low pressure turbines passing predetermined portions of the total fluid pressure at cqlal obtaining reduced power by cutting out one of said high pressure units and its connected low pressure unit.

5. In a marine turbine installation. a plurality of shafts each havingr a high pressure. unit and a low pressure unit`- a propeller shaft geared to both`of said shafts, means connecting the low pressure unit on each shaft in series with the high pressure. unit on the other shaft. said rrs|metive high and low pressure turbines passing predetermined unequal portions 't' the total lluid pressure at equal speeds ol revolution. and means for cutting out either ot said high pressure units and its connected low pressure unit to secure. diti'erent reduced powers.

6. Tn a marine turbine installationfa plurality of shafts each having a high pressure unit and alow pressure unit.. a propeller shaft geared to both ot' said shafts. means connecting the low., pressure. unit on each 13o l1,235,939 -gj shaft in series with the high lpressure unit on the other shaft, and a condenser connected to both ofisaid loiv pressure units.

7. ln a marine turbine installation, a plurality of shafts each having a high pressure unit and a low pressure unit, propeller shaft geared to both of said shafts, means eonneting the low pressure unit` on each shaftl in series with the high pressure unit lo on the other shaft, said respective high and low pressure turbines passing predetermined portions of the total fluid pressure at equal speeds of revolution, a condenser connected to both of said iowpressure units, and nieans i for obtaining` reduced power by cutting out one of said high pressure units-and its conii eted low pressure units independently of aid condenser. l f/ 8. ln a marine tui-bine installation, a pluiality of shafts each having a high pressure unit and a low pressure unit, a propeller shaft geared 'to toth of said shafts, ineens 4 connecting the low i'iressure iinit'on eaeh shaftin series with the high pressure unit on the other shaft, said respective high and low pressure turbines passing predetermined 'unequal portions ofthe tota-l fluid pressure :it equal speeds of revolution, a condenser connected to both of said low pressure units, and means for obtaining reduced power by cutting ou'hone of said high pressure units and its eonneoted low pressure units independently of said condenser.

9. In marine turbine installation, a pluiality (if shafts, one having a high pressure ii'iit and a single flow low pressure unit and the other having a high pressure unit and a divided flow low pressure unit, a pro- 'pel i er shaft geared to both of said shafts, a 4o series connection.. between eaeh high pres- ,ire unit and the low pressure unit 'on the itner. shaft, said geared shafts being driven.

/f at equal speed attiilljppwer.

10. ln a marine turbine installation, a plurality of shafts each having a high pressure unit and a low pressure unit, a propeller shaft geared to both of said shafts,

and ineans connecting the low pressure unit on each shaft in series with the high pres4` 5o sure unit on the other shaft, said low pressiire sections being bladed alike.

ll. ln a marine turbine installation, a. plurality of shafts, one having a high pressure unit and a single flow low pressure unit and the other having a high pressure unit and a divided flow low vpressure unit, a propeller shaft geared to both of said shafts,

' a series eonneetion between each high pressure unit and the low pressure unit on the other shaft, said single flow low pressure unit and eaeli see-tion of said divided "flow low pressure unit being, alike.

1Q. ln a turbine installation, a driven shafteariying a pearfa plurality of driving/'shafts each geared to said driven shaft `high pressure and al through said gear, a high pressure and a low pressure turbine unit on each shaft in separate easings, each low pressure unit being in series with the high pressure unit on the other shaft and adapted to pass unequal fractions of the total fluid pressure, and controllingmeans whereby to obtain three powers by using all of said high and low pressure units or one of each;

` 13. A turbine installation comprising a pair of high pressure turbine units on separate shafts, three low pressure units, two being on `one of'said shafts and the third on the other shaft, a driven shaft geared to both of said shafts, a series connection to the isolated low pressure unit from. the high pressure unit on the other shaft, and a connection between the other high pressure unit siinultaneQusly supplying` said remaining tivo low pressure units. g5 lai. A turbine installation comprising a pair of high pressure turbine units on separate shafts, three low pressure units, two being on one of said shafts and the third on the other shaft, a. driven shaft geared to' both of'said shafts, a series connection to the isolated low pressure unit from the high pressure unit on the other shaft, a eonnection between the other high pressure unit simultaneously supplying said remaining two low pressure units, and a reversing `turbine associated with said isolated low presl sure turbine.

l5. mai-ine turbine propulsion system comprising a propeller shaft carrying a gear, a plurality of driving shafts having interchangeable pinions geared thereto, a high pressure and a low pressure unit on one of said shafts, and a high pressure and 'two low pressure units on the other shaft, 105 a series connection from said first high pref sure unit for supplying said two low pres'- sure units on the other-shaft in multiple, and a series connection froin the other high pressure unit to the remaining low pi'es- 110 sure unit.

16. A marine turbine propulsion system eoing'irisinp,` a propeller shaft carrying `a gear a plurality of driving shafts having interil'iangeable piiiions geared thereto, a 115 low pressure unit on one of said shafts, and a high pressure and two low pressure units on the other shaft, a sei'lies Connection fromV said first highpressiire unit for supplying said two low pressure units on the other shaft in multiple, aseries connection from the'other high pressure unit to the remaining low pressure unit, `and a reversing turbine on the shafts.. carrying the single llow pressure unit. 17. ,AL turbine installation comprising'I a pair of high pressureturbineunits, andthree low pressure units, one of saidhigh pressure units being in series with one of said 'low pressure units, the other high'pressure unit 130 CII -the other high pressure beingV connected to simultaneously supply the remaining twolow pressure units, a shaft carrying one high pressure and one low pressure unit, a'second shaft carrying and remaining two low pressure units, one of said shafts having a coupling for disconnecting the high pressure unit, and a propeller shaft geared to both of said shafts.

18. In a marine turbine installation, a propeller shaft geared to two driving shafts, a high and a low pressure unit on each shaft, one of said .high pressure units developing greater power than the other, and one of said low pressure units developing greater power than the other, the low pressure unit of greater power: being on the same shaft with the high pressure unit of less power,

'and connections whereby the total power developed on each driving shaft is equal.

19. In a. marine turbine installation, a propeller shaft geared to two driving shafts, a high and a low pressure unit on each shaft, one of said high pressure units developing greater power than the other, and one of said low pressure units developing greater power than the other, the low pressure unit of greater power being on the same shaft with the high pressure unit of less power, and connections whereby the total power developed on each driving shaft is equal at equal speeds of said driving'shafts.

20. In a marine turbinev installation, a propeller shaft geared to two driving shafts, a high and a low pressure unit on each shaft, one of said high pressure units developing greater power than the other, and one of said low pressure units developing greater power than the other, the low pressure unit of greater power being on the same shaft with the high pressure unit of less power, and series connections between the high and low pressure units whereby the total power developed on each driving shaft at full power is equal.

21. In a marine turbine installation, a propeller shaft geared to two driving shafts,'a high and a low pressure unit on each shaft, one of said high pressure units developing greater power than the other, and one of said low pressure units developing greater power than the other, the low pressure unit of greater power being on the saine shaft with the high pressure unit of less power, and series connections between the high and low pressure units whereby the total power dev| ,Hped on each driving shaft at full power .(jequal at equal speeds of said driving shafts.

22. A turbine installation comprising a driven'shaft havingr a gear, a high and a'I low pressure turbine in tandem on each side of said gear and connected thereto, cross connections from each high pressure turbine to the low pressure turbine on the other shaft, and means for varying the total power applied to said gear without changing the proportion of power applied on each side.

23. A turbine installation comprising a driven shaft having a gear. a high and a low pressure turbine in tandem on each side of said gear and connected thereto, cross connections from each high pressure turbine to the low pressure turbine on the other shaft, and means for cutting out one high pressure unit on one side aud a low pressure unit on the other side without changing the proportion of pover applied on each side.

In testimony whereof I affix ture, in presence of two witnesses.

J. 'I-I. MoMAsTnns.

my signa- 8( 

